Homeowners and turfgrass managers in the United States rely on fewer than 20 plant species for all their grassing needs. Moreover, nearly all of these 20 grasses originate from the same general region of Eurasia. An estimated 46.5 million acres of turfgrasses are presently grown in the US (Grounds Maintenance magazine, May 1996, p. 10.). Concentrating this few number of species over a vast agricultural landscape is bound to produce problems over time as disease or insect organisms build up and become virulent against existing grasses. This type of pandemic actually occurred in the US in recent years, when large acres of the corn belt were decimated by an outbreak of southern corn leaf blight when a mutated strain of the disease arose.
The solution to this dilemma lies in species diversity. Agriculturists have found that by increasing the number and breadth of species, there is increased genetic diversity and less chance that a particular parasite will devastate a substantial acreage of plants.
Another factor urgently needed is diversity in where species originate. Most of the common turfgrasses grown in this country--Kentucky bluegrass (Poa pratensis L.), creeping bentgrass (Agrostis stolonifera L.), fine fescue (Festuca spp.), tall fescue (F. arundinacea Schreb.), and perennial ryegrass (Lolium perenne L.)--species that comprise the bulk of turf in the temperate zone--derive from the same region of Europe. Only one turfgrass species originates from here in North America (Buchloe dactyloides[Nutt.] Engelm.) and only two from Eastern Asia (Zoysia japonica Wild. and Eremochloa ophiuroides [Munro.] Hack). To increase the breadth of genetic origin, more turfgrasses are needed that originate from a broader sector of world geography, to bolster the diversity of today's turfgrasses.
Another advantage of developing additional turf species is to help reduce turf maintenance levels. Present-day turfgrasses are better suited to high maintenance than low. They perform best when given a steady diet of water, fertilizer, and chemical pesticides. In theory, grasses native to a particular locale should be able to withstand local growing conditions better than exotics, without the need for additives and preservatives. Grass species that can survive on less input of water or other scarce natural resources offer benefits for reducing maintenance and improving environmental friendliness of lawns.
But finding and developing new grass species from nature is difficult, time consuming, and expensive. The developer must sift through thousands of prospective grasses listed in botanical literature, identify promising grasses, and travel thousands of miles to locate, isolate, identify, transport, quarantine, grow, test, and breed these grasses. This process can take more than 10 years to develop acceptable cultivars. Furthermore, as it turns out, most prospective grasses in nature have no commercial turf value, due to their inability to generate an acceptable ground cover when mowed. The vast majority of natural grasses cannot produce a plush lawn under continuing defoliation.
Also, few grasses found in nature have the ability to produce marketable quantities of seed--a critical necessity for commercialization of a new grass species. Raw germplasm of most native grasses seldom tops 100 lbs. per acre in seed production (R. S. Sadasivaiah and J. Weijer, 1981, The utilization of native grass species for reclamation of disturbed land in the alpine and subalpine regions of Alberta. In Reclamation in mountainous areas. Proc. 6th ann. meeting Can. Land Reclam. Assoc.). This level of seed production is not high enough for economic viability. By contrast, popular grasses like tall fescue have been cultivated and selected since prehistoric times for cattle fodder. Only high yielding plant lines have persisted through the ages. Many of today's tall fescue cultivars top 1 ton per acre in seed production.
Yet another complexity facing the plant developer is the unresponsiveness of many wild grasses to plant breeding. The vast majority of wildland grasses lack genetic potential for refinement into desirable turfgrass cultivars. Only after considerable investment in collection and breeding does the developer discover which grass species can be successful bred and which cannot.
The Agrostis genus--better known as the bentgrasses--is comprised of over 100 species, several of which have been developed into successful turfgrasses. One Agrostis in particular, A. stolonifera or creeping bentgrass, has become the preeminent grass for golf course putting greens the world over. Another Agrostis species, colonial bentgrass (A. tenuis Sibth.), has been bred into a golf course grass useful on tees and fairways in cooler regions. Two or three other Agrostis species find minor turf application, mostly for golf, tennis courts, bowling greens, or an occasional home lawn.
The Agrostis genus is widely distributed throughout the world with representative species found on all of the northern continents. However, of the present-day bentgrass species in use as turfgrasses, all originated from Europe. The original seed of these plants was brought to the US during colonial times.
America has an abundance of native bentgrass species (A. S. Hitchcock, 1951, Manual of the grasses of the United States. USDA Misc. Publ. 200) but none are commercially useable as turf grass.
Agrostis idahoensis, or Idaho redtop, was first identified as a distinct species in 1897 when it was first published by Nash in the Torrey Botany Club Bulletin 24:42 (Heller 3431). Idaho bentgrass.RTM. is the trademarked name registered for this grass species by Jacklin Seed Company of Post Falls, Id.
Agrostis idahoensis is found in nature throughout the mountains of New Mexico, Arizona, and California, along the Rockies, and north to Fairbanks, Ak. Agrostis idahoensis is a bunch-type perennial grass, lacking lateral runners. Commercial bentgrass species (creeping bentgrass, colonial bentgrass, etc.) all possess stolons (above-ground running stems) and/or rhizomes (below ground running stems). Hitchcock describes Agrostis idahoensis as follows:
Culms slender, tufted, 10 to 30 cm tall, leaves mostly basal, the blades narrow; panicle loosely spreading, 5 to 10 cm long, the branches capillary, flexuous, minutely scabrous; spikelets 1.5 to 2.5 mm long; lemma about 1.3 mm long, awnless; palea minute. Differs from A. scabra in the smaller spikelets and in the narrower panicle with shorter flexuous branches. PA1 Delicate, loosely-tufted, glabrous, perennial, 10-30 cm high; blades flat, narrow, 1-6 cm long; panicle loose, green or purple, 5-10 cm long; rays capillary; spikelets about 1.5 mm long; lower glume scabrous on the keel, slightly larger than the upper; lemma truncate, awnless, 1 mm long; palea minute.
Piper and Beattie (Charles V. Piper and R. Kent Beattie, 1914, Flora of Southeastern Washington and adjacent Idaho, New Era Printing Co., Lancaster, Pa.) studied the natural occurrence of Agrostis idahoensis. They found it common to the alpine woods of the Craig Mountains. Their botanical description is as follows:
Correll and Correll (D. S. Correll and H. B. Correll, 1972, Aquatic and wetland plants of the Southwestern United States, Stanford Univ. Press, Stanford, Calif.) reported that Agrostis idahoensis is an important native wetland species in moist mountain meadows, swamps, shallow water of ponds, lakes, along streams, and on sand-gravel bars in river beds throughout the West. DeBenedetti and Parsons (S. H. DeBenedetti and D. J. Parsons, 1984, Postfire succession in a Sierran subalpine meadow, Amer. Midland Naturalist 111: 118-125) concluded that Agrostis idahoensis was the most important native grass species present in post-fire succession of subalpine grasslands in California. Its tenacious growth under adverse conditions makes it a valuable forage for wildlife.
In the mining districts of Northern Idaho, native stands of near 100% Agrostis idahoensis exist, where other grasses and forbs have long been eradicated through the continued runoff of mine pollution. Agrostis idahoensis is one of the few plants capable of surviving and prospering under these loads of heavy metals, making Agrostis idahoensis potentially valuable for reclamation of similarly affected sites.